Vertical tube heater



Dec. 13, 1960 J. w. THROCKMORTON ETAL 4,

VERTICAL TUBE HEATER Filed July 22, 1958 '2 Sheets-Sheet 1 E" /7 17 h.22 /5 Q j- 3; 33 32 fig 2 ma T T T INVENTORS w s. 14441 1 /J BY Dec.13, 1960 J. w. THROCKMORTON ETAL 2,964,033

VERTICAL TUBE HEATER 2 Sheets-Sheet 2 Filed July 22, 1958 INVENTORS JOHNW. THROC/(MOPTOA/ VERTICAL John W. Throckmorton and John -S.'Wa1lis,New:York,

N.Y., assignors, by mesne assignments, to Yuba Consolidated Industries,Inc., San Francisco, ,Calif., acorporation of Delaware Filed July 22,1958, Set. N0.'750,170

7 Claims. (Cl. 126-109) This invention pertains to vertical tube heatershaving a cylindrical shell, the arrangement of the tubes being such asto make the heater peculiarly well adapted for heating air or othergaseous material, although the heater is susceptible of more generaluse. Various objectsand advantages of the heater will hereafter appearand will be readily understood by those skilled in the .art.

Referring to the drawings:

Figure 1 is a partially sectional elevation which, for simplicity, omitsmost of the tubes except those at the vicinity of the cross section.

Fig. 2 .is a sectional .plan view taken on the line of Fig. 1 and, forsimplicity, shows :only a small group of the total number of tubes,which are uniformly spaced in a circumferential direction within theheater. The supporting beams for the stack are omitted in this view.

Fig. 3 is a partial view corresponding to Fig. 1 illustrating a type ofpreheater or economizer section which may be employed to absorb a largerproportion of the heat from the flue gases before they escape into thestack.

In the structure of Figs. 1 and 2, to which special reference may now behad, the furnace shell is preferably a cylinder of large diameterrelative to its height, having a bottom plate 11 which supports a groupof central burners 12 which may, if desired, be replaced by a singleburner and a plurality of outer burners 13 which are spaced in a circle,as shown in Fig. 2.

The furnace shell 10 is supported by a plurality of structural steellegs 14, only two of which are illustrated, and which are welded to thefurnace shell 10. A top plate 15 is mounted on the furnace shell nearthe top and preferably welded thereto. It has a large central openingand carries a concentric cylindrical stack 16. A plurality of structuralsteel triangular supports 17, only two of which are shown, mounted onthe furnace at the top, support the stack 16 and have overhanging lugs18 which extend a short distance down from the top of the furnace shelland are welded thereto.

A plurality of coils 20, each of which is preferably formed of a singlebent tube having a relatively large diameter bend at the top and twoparallel legs 21 extend downwardly through the bottom of the heater. Thecoils are supported from the triangular frame 17 at the top of theheater by hangers 22.

Below the bottom of the heater is a large circular inlet manifold 30 inthe form of a hollow torous ring 23 to which all of the outer legs ofthe coils are connected as indicated at 24. The inner legs are similarlyconnected to a concentric torous ring 31 of smaller diameter, asindicated at 25.

All of the burners 12 and 13 are upshot, and the flame and hot gasesfrom the burners 12 extend upwardly in an axial direction through thecenter of the heater until diverted by conical baifle 32 which issupported by hangers 33 from the top plate 15 of the heater. The apex ofthe conical baflie is downward and the base of the cone 2,96i,33Patented Dec. l3, i960 is at the top and is spaced from the "top plate15 so that the hot gases eventually flowinwardly and up the stack 16.

The inner legs of :the coils areheated primarily by radiation from thecentral column of flame and hot gases just described. Additional flamesand hot gases rise from the burners 13 between the inner and outer legsof the .coils and largely .give up heat by radiation to the outer sidesurfaces 'of the inner legs of the coils and to the inner side surfacesof the outer legs of the coils.

The outer surfaces of the outer legs of the coils are largely heated byreradiation from the furnace shell 10, the inner surface of which ispreferably provided with a refractory lining 10a. The gases arising fromburners 13, after having given up a large part of their heat byradiation, bathe the upper bends of the coils and flow inwardly and upthe stack. The inlet manifold 30 has inlet pipes 35 and the outletmanifold 31 has outlet .pipes 36.

The heater is particularly welladapted for heating air .or othergaseoussubstances, since the large inlet and outlet manifolds provide vaready distribution and equalization of thefluid supply to the outer legsof the coils. Like- .wise the outlet manifold is large and insures agood distribution of the highly heated gaseous .substance flowingdownwardly through the inner legs of the coils.

It is of special importance that the outer legs of the .coils, which aresupplied with the gaseous fluid to be heated, which would normally be atmoderate temperature, are heated by radiation only on the inner surfacesand by reradiation on the outer surfaces, since they absorb heat readilydue to the great difference in temperature between the flames and thegaseous fluid. On the other hand, the gaseous fluid, which is alreadyhighly heated before it enters the inner legs of the coils and flowsdownwardly, is subjected to intense radiant heat on both the inner andouter surfaces by reason of the burners 12 in the center of the heaterand the burners 13 between the legs of the coils.

In Fig. 3 like parts are designated by the same reference characters,and here the conical baffle 32 and supports 33 are omitted, and aneconomizer coil 40 comprising a nest of tubes with extended surfacemeans thereon largely fills the space in the lower end of the stack andthus increases the efiiciency of the heater by lowering the temperatureof the flue gas before it is per mitted to escape up the stanck 16. Thenest of tubes which makes up the economizer coil 40 is supported byhangers 41 from cross rods which form a grid 42 without interfering withthe upward flow of the flue gases. The economizer has an inlet pipe 43and an outlet pipe 44. The economizer may be connected with a source ofair or gas to be heated prior to its introduction into the inletmanifold 30 of the main heater.

While the heater illustrated and described is well adapted for heatingair and the like, it can be built with a very much taller furnace shelland very much longer coils and also, if desired, may be utilized forheating oil or other liquids. The radius bends at the top of the coilsare such as to permit the tubes to be bent into the desired shape, andno return bends of the ordinary construction are necessary or employed.

By reference to Fig. 2, it appears that by reason of the difference indiameter between the inlet and outlet manifolds, the outer legs of thetubes 20 are spaced substantially from one another and from the Wall ofthe heater. This is preferable to enhance the reradiation effects fromthe refractory lined furnace wall.

On the other hand, the inner legs are close together and the coils arepreferably made with alternately wider and narrower spacing between thelegs so that they are more readily accommodated at the inner circlewhere they join the outlet manifold.

Other modifications of this invention may be made without departing fromits fundamental aspects, and hence we desire that only such limitationsbe imposed as are indicated in the appended claims.

What we claim:

1. A heater comprising a vertical cylindrical furnace chamber having arefractory wall, a top plate attached to the cylindrical furnace chamberand having a central flue gas outlet, a bottom plate attached to thechamber at the bottom, a plurality of inverted U-shaped tube units eachcomposed of two widely spaced vertical leg tubes and a large diameterreturn bend at the top, said tube units being circumferentiallydistributed around the axis of the chamber in radial planes, hangerssupporting the tube units from the top plate so that the outer leg tubesare close to but spaced from the refractory wall of the chamber and fromeach other and form a single cylindrical bank of vertical tubes and theinner leg tubes are Widely spaced from the outer leg tubes so that theinner leg tubes form a concentric cylindrical bank of vertical tubeswhich produce an unobstructed interior combustion chamber, the twoconcentric cylindrical tube banks forming an unobstructed annularcombustion chamber, at least one central burner in the bottom plateadapted to discharge flame and hot combustion products into saidunobstructed interior combustion chamber and a circle of burners in thebottom plate adapted to discharge flame and hot combustion products intosaid unobstructed annular combustion chamber formed between the twoconcentric cylindrical tube banks whereby heat is applied by directradiation on both sides of the inner bank of vertical tubes and on theinner side of the outer bank and by reradiation fromthe refractory wallof the furnace chamber on the outer side of the outer bank, andinterconnecting means for the tubes near the bottom of the furnace.

2. The furnace structure of claim 1 in which concen tric manifold ringsto which the outer and inner vertical tube banks are respectivelyconnected constitute the interconnecting means.

3. The furnace structure of claim 2 in which the concentric manifoldsare disposed below the bottom plate and the tube banks extend throughthe bottom plate to connect therewith.

4. The furnace structure of claim 1 in which an inverted conical baffieis centrally mounted near the top of the furnace chamber.

5. The furnace structure of claim 2 in which an inverted conical bafiieis centrally mounted near the top of the furnace chamber.

6. The furnace structure of claim 1 in which a flue or stack extendsvertically upward and is mounted on the top plate at the flue gas exit.

7. The furnace structure of claim .1 in which a flue or stack extendsvertically upward and is mounted on the top plate at the flue gas exitand an economizer disposed therein.

References Cited in the file of this patent UNITED STATES PATENTS2,524,637 Ruegg Oct. 3, 1950 2,725,873 Walter Dec. 6, 1955 2,789,521Wasp Apr. 23, 1957 2,796,052 Throckmorton et al June 18, 1957

